Generally, a smart key, also referred to as a key fob, of a vehicle is a device that allows a user, i.e., a driver, to open and close a door and start the vehicle without inserting a separate key or operating buttons.
The user can start the vehicle only with the smart key, however, in the case of a connected car, the vehicle is started remotely through a telematics service, and the user enters the vehicle and switch it to a general starting mode.
Meanwhile, as research on the connected car has been increasing, a smart-key-free starting method has been developed in which the user directly starts the vehicle using his/her smart phone, i.e., a mobile device, without the smart key.
Accordingly, a connected car service provides a service using digital key technology, for opening the doors or starting the vehicle through the mobile device using NFC (Near Field Communication)/BLE (Bluetooth Low Energy), and the technology is widely used in common door locks and remote control applications.
Particularly, in a method using digital keys based on the mobile device, since the vehicle is directly connected to the mobile device without communicating with a server over a telecommunications network, the vehicle can be operated without any problem even in an out-of-service area, and since no telecommunication service is used, no additional cost is required.
In addition, since the digital keys based on the mobile device can be shared, a person who has access to the shared digital keys based on the mobile device can use the vehicle without an additional procedure.
Herein, in vehicle-sharing according to sharing of the digital keys based on the mobile device, various restrictions may be imposed. For example, the restrictions may be that the vehicle can only be used for 3 hours, or only the trunk can be open.
However, since a replay attack, which uses random digital keys of the mobile device, on the vehicles not connected to the Internet is possible, there is a risk of theft of the vehicles which uses the digital keys based on conventional mobile communication.
In addition, conventionally, the digital keys based on the mobile device can be generated indefinitely without regard to an actual key, which makes it difficult to manage the digital keys. That is, as the number of the digital keys generated for a single vehicle increases, the management of the digital keys becomes more difficult.
In addition, when the digital keys based on the mobile device are provided as encrypted SMSs for vehicle-sharing, the encrypted SMSs can be decrypted by another person, thus illegal use of the digital keys is difficult to prevent.
Conventionally, in order to share a vehicle, a user has to continuously delete and newly receive digital keys, and when the vehicles of different manufacturers are shared, the user has a limit in using an app on the mobile device, or the user must use a plurality of apps corresponding to the different manufacturers.
In addition, conventionally, there is a difficulty in managing the digital keys due to a compatibility of an app store update and an operation system of the mobile device which has a registered digital key for vehicle-sharing.
In addition, even when a conventional vehicle-sharing service using a digital key based on a mobile device is provided, a large amount of resources are required to perform management of a start and a termination of the vehicle-sharing, user management for vehicle-sharing, and billing management, etc.